Conveyor chain structure

ABSTRACT

A conveyor structure including a power track in which a conveyor chain travels and a free track along which free trolleys travel. The conveyor chain includes alternate main links that the pivotally interconnected by alternate pairs of upper and lower links through pivot pins. The construction of the links and pivot pins is such that there is permissible movement between the main links and the pivot pins about horizontal axes and permissible movement between the pairs of links and pivot pins about vertical axes. In one form, the conveyor comprises a tow line conveyor structure including a floor having a track slot therein through which the tow pin of carriers or tow carts is adapted to extend and a chain supporting structure beneath the slot. In another form, the conveyor comprises an overhead power and free conveyor comprising a load supporting free track on which the carriers are movable and a power track in which the conveyor is moved.

United States Patent 11 1 Karlstrom Nov. 27, 1973 [73] Assignee:American Chain & Cable Company Inc., New York, NY.

221 Filed: Nov. 8, 1971 21 Appl. No.: 196,386

[56] References Cited UNITED STATES PATENTS 12/1970 Dehne f. 104/172 C3,438,338 4/1969 Bildsoe et a1. 104/172 C 2,952,162 9/1960 Thibault74/254 FOREIGN PATENTS OR APPLICATIONS 211,802 3/1967 Sweden 198/189Primary Examiner-Robert G. Sheridan Assistant ExaminerRobert SaiferAtt0meyArthur Raisch et al.

[5 7 ABSTRACT A conveyor structure including a power track in which aconveyor chain travels and a free track along which free trolleystravel. The conveyor chain includes alternate main links that thepivotally interconnected by alternate pairs of upper and lower linksthrough pivot pins. The construction of the links and pivot pins is suchthat there is permissible movement between the main links and the pivotpins about horizontal axes and permissible movement between the pairs oflinks and pivot pins about vertical axes. In one form, the conveyorcomprises a tow line conveyor structure including a floor having a trackslot therein through which the tow pin of carriers or tow carts isadapted to extend and a chain supporting structure beneath the slot. inanother form, the conveyor comprises an overhead power and free conveyorcomprising a load supporting free track on which the carriers aremovable and a power track in which the conveyor is moved.

13 Claims, 13 Drawing Figures PATENTEU NOV 2 7 I975 mu E CONVEYOR CHAINSTRUCTURE This invention relates to conveyors and particularly toconveyor structures.

BACKGROUND OF THE INVENTION In conveyor systems such as overhead powerand free conveyor systems and tow line conveyor systems, conveyor chainsare provided for moving the carriers along a track which in the case ofan overhead conveyor is a free track and in the case of a tow lineconveyor is the floor. In an overhead conveyor system, the wheeledcarriers are moved along a free track by the conveyor which operates ina power track and has means thereon for engaging the carriers on thefree track.

In tow line conveyor systems, wheeled carriers are moved along a floorby a conveyor positioned beneath the floor which are engaged by tow pinsextending through a slot in the floor to engagement with the conveyor.In such conveyor systems, it is desirable to provide a conveyor or chainthat will have a minimum vertical height but at the same time will besubject to permissible flexing or pivoting about both horizontal andvertical axes.

Among the objects of the invention are to provide a conveyor systemwherein the conveyor occupies minimum vertical height and width; whereinthe conveyor chain is permitted to pivot or bend in both horizontal andvertical directions; which can be assembled and disassembled readily atany point; will operate in an enclosed track; which has minimum wear;and which can be produced at relatively low cost.

SUMMARY OF THE INVENTION A power and free conveyor structure including afree track along which trolleys are moved and a power track in which aconveyor chain operates. A conveyor chain is positioned on the chainsupporting structure and includes alternate main links that arepivotally interconnected by alternate pairs of upper and lower linksthrough pivot pins. The construction of the links and pivot pins is suchthat there is permissible movement between the main links and the pivotpins about horizontal axes and permissible movement between the pairs oflinks and the pivot pins about vertical axes.

In one form, the conveyor comprises a tow line conveyor structureincluding a floor having a slot therein through which the towpin ofcarriers is adapted to extend and a chain supporting structure beneaththe slot. In another form, the conveyor comprises an overhead power andfree conveyor comprising a load supporting free track on which thecarriers are movable and a power track in which the conveyor is moved.

DESCRIPTION OF THE DRAWINGS FIG. 1 is a part-sectional side elevationalview of a tow line conveyor system embodying the invention.

FIG. 2 is a side elevational view of the chain on an enlarged scale of aportion of the conveyor shown in FIG. 1,

FIG. 3 is a fragmentary sectional view on an enlarged scale taken alongthe line 3-3 in FIG. 1.

FIG. 4 is a fragmentary part-sectional plan view of a portion of theconveyor shown in FIG. 2.

FIG. 5 is a perspective view of a chain pin.

FIG. 6 is a fragmentary plan view showing the chain parts in a differentoperative position for assembly and disassembly.

FIG. 7 is a fragmentary plan view of another part of the conveyor chain.

FIG. 8 is a part-sectional fragmentary elevational view of a power andfree conveyor system embodying the invention.

FIG. 9 is a fragmentary sectional view of an enlarged scale taken alongthe line 9-9 in FIG. 8.

FIG. 10 is a fragmentary sectional view on an enlarged scale taken alongthe line l0l0 in FIG. 8.

FIG. 11 is a fragmentary part-sectional plan view of a portion of theconveyor shown in FIG. 8.

FIG. 12 is a fragmentary plan view on an enlarged scale showing aportion of the conveyor chain structure of the form of the inventionshown in FIG. 11.

FIG. 13 is a fragmentary elevational view of a portion of the conveyorchain showing the parts in a difi'erent.

operative position.

DESCRIPTION The invention relates to a conveyor chain such as used in,but not limited to, tow line conveyor systems and power and freeconveyor systems. Referring to FIG. 1, the tow line conveyor systemembodying the invention comprises a plurality of carriers 10 which aremovably supported on a floor 11 by wheels l2, 13. Each carrier 10includes a tow pin 14 that extends downwardly through a slot 15 in thefloor 11 into engagement with a conveyor for moving the carrier in apredetermined path along the floor I].

As shown in FIG. 3, a chain supporting structure 16 comprising spacedwalls 17 is provided beneath the floor to define side wall surfaces 18and bottom wall surfaces 19-for receiving a conveyor chain.

As shown in FIG. 2, the conveyor chain comprises alternate main links 20that are pivotally connected to alternate pairs of upper and lower links2] by pivot pins 22. Each main link 20 comprises a central body 23 andends 24 that extend axially from the ends of the body 23 intermediatethe top and bottom surfaces thereof. The body 23 of each main link 20includes opposed flat surfaces 25, 26, the surface 26 having asubstantially lesser longitudinal extent to define a recess 27. Whenpositioned as shown on the left in FIG. 2, with the surface 26 facingdownwardly and engaging bottom wall surfaces 19, the link 20 constitutesa main chain supporting link. When reversed as shown on the right inFIG. 2 with the surface 25 extending downwardly, the recess 27 defines apushing dog 28 for engaging the tow pin 14. If desired, an additionalprojection 29 can be welded to the link 20 on surface 26, when it is inthe position shown on the right in FIG. 2, to obtain greater verticalsurface contact with the tow pin 14.

As shown in FIG. 7, a generally rectangular opening 30 is provided ineach end 24 of the link 20. The outermost edge 31 of each opening 20 isconvex in vertical cross section and straight in horizontal crosssection (FIGS. 1, 7).

As shown in FIGS. 2, 4 and 6, links 21 are identical and have an axiallyelongated opening 32 therein that has a greater length than width and agenerally annular recess 33 in the outer surface thereof for purposespresently described. As shown in FIG. 2, each link has a flat outersurface 34 and flat surface 34 of the lowermost link 21 engages the basesurfaces 19 of the chain supporting structure 16.

Referring to FIG. 5, each pivot pin 22 includes a central enlarged bodyportion 35 that has a transverse horizontal recess 36 therein which isconcave in vertical cross section and straight in horizontal crosssection and an opposed convex surface 37. Each pivot pin 22 furtherincludes transverse end portions 38 connected to the central portion 35by intermediate portions 39. Intermediate portions 39 are generallycylindrical and have a diameter substantially equal to the width ofopening 32 of links 21. The transverse end portions 38 have a width in adirection transversely of the pin that is substantially equal to thewidth of the opening 32 of link 21 and a length substantially equal tothe diameter of recess 33 and the length of opening 32.

In order to assemble the conveyor chain, a pivot pin 22 is brought intoposition and placed in the opening 30 of a link with the recess 36engaging the surface 31. Links 21 are then positioned over theprojections 38 with the long dimensions of projections 38 aligned withthe long dimensions of openings 32 as shown in FIG. 6. After the links21 are inserted over the projections 38, the links 21 are rotated 90causing the transverse projections 38 to assume the relationship asshown in FIG. 4.

When assembled, the conveyor chain provides substantially no movementabout a vertical axis and permissible movement about a horizontal axisbetween the main links 23 and the pivot pin 22 as shown in broken linesin FIG. 2; and the construction provides substantially no permissiblemovement about a horizontal axis and permissible movement about avertical axis between the links 21 and the pivot pins 22.

It can be appreciated that the chain can be disassembled at any pointalong the link thereof for replacement or repair.

Referring now to FIGS. 8-13, the power and free conveyor systemembodying the invention comprises a power track 40 in which a conveyorchain 41 made in accordance with the invention is driven. The systemfurther comprises a free track 42 in which trolleys or carriers 43having wheels 44 thereon are operated. The chain includes a plurality ofpushers 45 that extend downwardly through a slot 46 into engagement witha pusher dog 47 on the carrier 43.

As shown in FIG. 8, the conveyor chain comprises alternate main links20' that are pivotally connected to alternate pairs of upper and lowerlinks 21 by pivot pins 22'. each main link 20' comprises a central body23' and ends 24' that extend axially from the ends of the body 23'intermediate the top and bottom surfaces thereof. The body 23 of eachmain link 20' rotatably supports wheels 48 that are mounted on a pin 49.Wheels 48 engage track 40 (FIG. 8). Wheels 48 are also rotatablysupported between links 21 and engage the side walls of track 40.

As shown in FIGS. 8 and 9, an opening 30' is provided in each end 24 ofthe link 20'. The outermost edge 31' of each opening 20' is convex invertical cross section and straight in horizontal cross section (FIGS.1, 7).

As shown in FIGS. 11-13, links 21 are identical and have an axiallyelongated opening 32' therein that has a greater length than width.

Referring to FIG. 13, each pivot pin 22' includes a central enlargedbody portion 35 that has a transverse horizontal recess 36' thereinwhich is concave in vertical cross section and straight in horizontalcross section and an opposed convex surface 37 Each pivot pin 22 furtherincludes transverse end portins 38' connected to the central portion 35by intermediate portions 39. Intermediate portions 39' are generallycylindrical and have a diameter substantially equal to the width ofopening 32 of links 21. The transverse end portions 38 have a width in adirection transversely of the pin that is substantially equal to thewidth of the opening 32' of link 21' and a length substantially equal tothe length of opening 32'.

In order to assemble the conveyor chain, a pivot pin 22 is brought intoposition and placed in the opening 30' of a link 20 with the recess 36'engaging the surface 31. Links 21' are then positioned over theprojections 38 aligned with the long dimensions of openings 32' as shownin FIG. 6. After the links 21' are inserted over the projections 38, thelinks 21 are rotated causing the transverse projections 38 to assume therelationship as shown in FIG. 9.

When assembled, the conveyor chain provides substantially no movementabout a vertical axis and permissible pivotal movement about ahorizontal axis between the main links 23 and the pivot pin 22' as shownin FIG. 13; and the construction provides substantially no permissiblemovement about a horizontal axis and permissible movement about avertical axis between the links 21 and the pivot pins 22' as shown inFIG. 12.

It can be appreciated that the chain can be disassembled at any pointalong the link thereof for replacement or repair.

I claim:

1. In a conveyor system, the combination comprising load supportingmeans along which carriers are moved in a predetermined path,

supporting means mounted along said load supporting means defining aconveyor chain supporting structure including a side wall and a basewall, and a conveyor chain in said supporting means comprising aplurality of alternate main links, alternate pairs of upper and lowerlinks between said main links,

each said main link comprising a central body and ends,

at least some of the main links having interengaging means forselectively engaging a carrier,

each said end having a vertically extending opening therein, the axiallyoutermost portion of said opening being substantially straight intransverse cross section,

each said opening of said main link being elongated in an axialdirection with respect to the main link,

each said pair of said upper and lower links including an openingtherein which is elongated in an axial direction, I

a pivot pin extending through each said opening of each end of said mainlink and said openings in one end of said pairs of links,

each said pivot pin having a centrally enlarged body portion,transversely extending end portions having a length in a directiontransversely of the pair of links which is greater than the width of theopenings in said links, and an intermediate interconnecting portionwhich has a width less than the transverse dimension of said centralenlarged portion and said transverse end portions,

said centrally enlarged body portion of each said pivot pin having asurface engaging the outermost edge of the respective opening of themain link, said surface being convex in vertical cross section andsubstantially straight in horizontal cross section whereby there issubstantially no permissible movement between said main link and saidpivot pin about a vertical axis but at least permissible pivotalmovement about a horizontal axis between the main link and the pivotpin, and there is no permissible movement about a vertical axis betweenthe pairs of links and the pivot pin.

2. The combination set forth in claim 1 wherein said centrally enlargedbody portion of each said pivot pin has a transverse surface on the sideopposite to that of the first-mentioned surface on said intermediateportion, said surface being convex in vertical cross section.

3. The combination set forth in claim 1 wherein said intermediateportion of each said pivot pin is circular in cross section.

4. The combination set forth in claim 1 wherein said intermediateportion of each said pivot pin is cylindrical.

5. The combination set forth in claim 1 wherein at least one wheel isrotatably supported on the body of at least some of the main links.

6. The combination set forth in claim 1 wherein the outermost edge ofthe opening in each said main link is generally curved in vertical crosssection.

7. The combination set forth in claim 1 wherein each said link of saidpair of links includes a generally annular recess in the outer surfacethereof.

8. The combination set forth in claim 7 wherein the depth of said recessin each said pair of links is substantially equal to the thickness of atransversely extending end portion of the pivot pin.

9. The combination set forth in claim 1 wherein said load supportingmeans comprises a floor having a slot therein through which the tow pinof a carrier is adapted to extend.

10. In a power and free conveyor system, a conveyor chain comprising aplurality of alternate main links,

at least some of the main links having interengaging means forselectively engaging a carrier,

alternate pairs of links,

each said main link comprising a central body and ends,

each said end having a vertically extending opening therein,

the axially outermost portion of said opening being substantiallystraight in transverse cross section,

each said opening of said main link being elongated in an axialdirection with respect to the main link,

each said pair of said upper and lower links including an openingtherein which is elongated in an axial direction,

a pivot pin extending through each said opening of each end of said mainlink and said openings in one end of said pair of links,

each said pivot pin having a centrally enlarged body portion,

transversely extending end portions having a length in a directiontransversely of the pair of links which is greater than the width of theopenings in said links, and an intermediate interconnecting portionwhich has a width less than the transverse dimension of said centralenlarged portion and said transverse end portions,

said centrally enlarged body portion of each said pivot pin having asurface engaging the outermost edge of the respective opening of themain link, said surface being convex in vertical cross section andsubstantially straight in horizontal cross sec tion whereby there issubstantially no permissible movement between said main link and saidpivot pin about a vertical axis but at least permissible pivotalmovement about a horizontal axis between the main link and the pivot pinand there is no permissible movement about a horizontal axis but atleast permissible movement about a vertical axis between the pairs oflinks and the pivot pin.

11. The combination set forth in claim 10 wherein said centrallyenlarged body portion of each said pivot pin has a transverse surface onthe side opposite to that of the first-mentioned surface on saidintennediate portion, said surface being convex in vertical crosssection.

12. The combination set forth in claim 11 whereinsaid intermediateportion of each said pivot pin is circular in cross section.

13. The combination set forth in claim 12 wherein said intermediateportion of each said pivot pin is cylindrical.

UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No.3,774,545 Dated November 27, 1 973 Inventor(s) Karl R. M. Karlstrom Itis certified that error appears in the above-identified patent and thatsaid Letters Patent are hereby corrected as shown below:

Column 5, line 11, after 'a', insert --horizontal axis but at leastpermissible movement about a-- Signed and sealed this ll th day of May197b,.

SEAL) At te s t v EDWARD M .FLET CHER R C MARSHALL DANE Atte stingOfficer j Commissioner of Patents FORM PC4050 (IO-69 uscoMM-oc scan-Pooi "J. GOVIIIIIIN'I PRINTING O'IICI "I O-Jll-Jl4

1. In a conveyor system, the combination comprising load supportingmeans along which carriers are moved in a predetermined path, supportingmeans mounted along said load supporting means defining a conveyor chainsupporting structure including a side wall and a base wall, and aconveyor chain in said supporting means comprising a plurality ofalternate main links, alternate pairs of upper and lower links betweensaid main links, each said main link comprising a central body and ends,at least some of the main links having interengaging means forselectively engaging a carrier, each said end having a verticallyextending opening therein, the axially outermost portion of said openingbeing substantially straight in transverse cross section, each saidopening of said main link being elongated in an axial direction withrespect to the main link, each said pair of said upper and lower linksincluding an opening therein which is elongated in an axial direction, apivot pin extending through each said opening of each end of said mainlink and said openings in one end of said pairs of links, each saidpivot pin having a centrally enlarged body portion, transverselyextending end portions having a length in a direction transversely ofthe pair of links which is greater than the width of the openings insaid links, and an intermediate interconnecting portion which has awidth less than the transverse dimension of said central enlargedportion and said transverse end portions, said centrally enlarged bodyportion of each said pivot pin having a surface engaging the outermostedge of the respective opening of the main link, said surface beingconvex in vertical cross section and substantially straight inhorizontal cross section whereby there is substantially no permissiblemovement between said main link and said pivot pin about a vertical axisbut at least permissible pivotal movement about a horizontal axisbetween the main link and the pivot pin, and there is no permissiblemovement about a vertical axis between the pairs of links and the pivotpin.
 2. The combination set forth in claim 1 wherein said centrallyenlarged body portion of each said pivot pin has a transverse surface onthe side opposite to that of the first-mentioned surface on saidintermediate portion, said surface being convex in vertical crosssection.
 3. The combination set forth in claim 1 wherein saidintermediate portion of each said pivot pin is circular in crosssection.
 4. The combination set forth in claim 1 wherein saidintermediate portion of each said pivot pin is cylindrical.
 5. Thecombination set forth in claim 1 wherein at least one wheel is rotatablysupported on the body of at least some of the main links.
 6. Thecombination set forth in claim 1 wherein the outermost edge of theopeNing in each said main link is generally curved in vertical crosssection.
 7. The combination set forth in claim 1 wherein each said linkof said pair of links includes a generally annular recess in the outersurface thereof.
 8. The combination set forth in claim 7 wherein thedepth of said recess in each said pair of links is substantially equalto the thickness of a transversely extending end portion of the pivotpin.
 9. The combination set forth in claim 1 wherein said loadsupporting means comprises a floor having a slot therein through whichthe tow pin of a carrier is adapted to extend.
 10. In a power and freeconveyor system, a conveyor chain comprising a plurality of alternatemain links, at least some of the main links having interengaging meansfor selectively engaging a carrier, alternate pairs of links, each saidmain link comprising a central body and ends, each said end having avertically extending opening therein, the axially outermost portion ofsaid opening being substantially straight in transverse cross section,each said opening of said main link being elongated in an axialdirection with respect to the main link, each said pair of said upperand lower links including an opening therein which is elongated in anaxial direction, a pivot pin extending through each said opening of eachend of said main link and said openings in one end of said pair oflinks, each said pivot pin having a centrally enlarged body portion,transversely extending end portions having a length in a directiontransversely of the pair of links which is greater than the width of theopenings in said links, and an intermediate interconnecting portionwhich has a width less than the transverse dimension of said centralenlarged portion and said transverse end portions, said centrallyenlarged body portion of each said pivot pin having a surface engagingthe outermost edge of the respective opening of the main link, saidsurface being convex in vertical cross section and substantiallystraight in horizontal cross section whereby there is substantially nopermissible movement between said main link and said pivot pin about avertical axis but at least permissible pivotal movement about ahorizontal axis between the main link and the pivot pin and there is nopermissible movement about a horizontal axis but at least permissiblemovement about a vertical axis between the pairs of links and the pivotpin.
 11. The combination set forth in claim 10 wherein said centrallyenlarged body portion of each said pivot pin has a transverse surface onthe side opposite to that of the first-mentioned surface on saidintermediate portion, said surface being convex in vertical crosssection.
 12. The combination set forth in claim 11 wherein saidintermediate portion of each said pivot pin is circular in crosssection.
 13. The combination set forth in claim 12 wherein saidintermediate portion of each said pivot pin is cylindrical.